Endocrinology Flashcards
anterior vs posterior pituitary hormones?
made and stored in anterior. only stored in posterior (made in hypothalamus)
anterior pituitary hormones
GH, prolactin, TSH, LH, FSH, ACTH
-blood supply
posterior pituitary hormones
ADH, oxytocin
-neural supply
prolactin
- needed for lactation
- usually inhibited, unless after childbirth
LH and FSH deficiency
- dec libido
- dec axillary, pubic, body hair
- erectile dysfunction
- no testosterone
- no menstruation
Kallman syndrome
dec FSH & LH
dec GnRH
anosmia
=hypogonadal + dec smell
metyrapone
inhibits 11-beta hydroxylase –> dec cortisol
- tests pituitary –> ACTH should rise; if not, the pituitary is damaged
- insulin stimulation = another test (hypoglycemia should stimulate GH release)
central diabetes insipidus
- brain damage (hypothalamus or posterior pituitary)
tx: vasopressin (desmopressin)
nephrogenic diabetes insipidus
- kidney does not respond to ADH
- hyperCa, hypoK, amyloid, myeloma, sickle cell disease
- tx: hydrochlorothiazide, NSAIDs, amiloride
- excessive thirst, polydipsia. volume depletion –> hyperNa –> neurologic symptoms
diabetes insupidus
- low urine osmolality
- low urine sodium
- high serum osmolality
- elevated urine volume
- serum Na maintained with appropriate fluid intake
acromegaly
- elevated GH
- MEN 1 syndrome: parathyroid + pancreatic cancer
-inc hat, ring, shoe size –inc soft tissue size
- carpal tunnel, OSA, body odor, teeth widening, deep voice, macroglossia, colonic polpys (–> cancer), arthralgia
- HTN, hyperglycemia, hyperlipidemia
- n: glucose suppresses GH
- not in acromegaly
-tx: surgery, cabergoline (dopamine agonist), octreotide (somatostatin analog), lanreotide, pegvisomant, radiotherapy
hyperprolactinemia causes
- pregnancy
- cutting pituitary stalk ( =loss of neg feedback)
- antipsychotics (dopamine antagonists)
- TCAs
- SSRIs
- methyldopa
- opiods
- metaclopromide
hyperprolactinemia px
- galactorrhea
- amenorrhea
- infertility
- erectile dysfunction
- dec libido
hyperprolactinemia dx & tx
-look at liver/ renal/ thyroid/ medication causes before MRI
- dopamine agonists (cabergoline)
- surgery (when not responding to meds)
TH
acts on Na/K ATPase
- hypoTH –> fatigue, dec reflexed, cold intolerance
- hyperTH –> anxiety, restlessness, hyperreflexia, heat intolerance, fever
hypoTH
causes:
thyroiditis (Hashimoto)
dietary deficiency of I
amiodarone
- slow, except menstruation inc
- dx: elevated TSH
- tx: synthroid
Graves disease
- hyperTH
- eye proptosis, skin findings
- TSH-R antibodies
- elevated radioactive iodine uptake
- steroids tx for proptosis
- tx: radioactive iodine
subacute thyroiditis
painful thyroid
-tx: ASA
thyroid adenoma
high TSH and high T4
- other forms of hyperTH have low TSH
- tx: surgery removal
thyroid storm tx
-propranolol: blocks target organ effects (B1 & B2), prevents conversion T4–>T3
- methimazole
- PTU: block TH production via thyroid peroxidase inhibition
-radioactive iodine (ablation); can result in hypoTH
fine needle biopsy
- only for normal-functioning thyroid
- only means to dx cancer
-iodine uptake study for hyper-functioning thyroid
medullary thyroid carcinoma
- arises from C cells
- elevated calcitonin –> flushing, diarrhea, pruritis
hyperCa causes
- primary hyperPTH
- cancer
- vit D intoxication
- sarcoidosis
- thiazide diuretics (DCT)
- hyperTH (inc osteoclast activity)
- metastases to bone
- MM
hyperCa px
confusion constipation bone lesions kidney stones (nephrolithiasis) DI --> volume loss (diuresis) renal insufficiency (prerenal) short QT syndrome
hyperCa tx
- massive saline hydration (NOT loop diuretics)
- bisphosphonates: pamidronate, zolendronic acid
- calcitonin: tachyphylaxis (wears off quickly); fast acting
- prednisone for sarcoidosis
hyperPTH causes & dx & tx
- solitary adenoma
- hyperplasia of all 4 glands
- DEXA scan
- image neck prior to surgery (look for edematous gland)
-surgical removal
hyperPTH symptoms
- osteoporosis
- nephrolithiasis
- muscle weakness
- anorexia, n/v
- abdominal pain
- PUD (Ca stimulates gastrin)
- high Ca, low phosphate
- short QT
- alk phos elevated
hypoCa
- twitchy, hyper excitable due to dec threshold for depolarization
- -> easier to depolarize
- Chvostek sign (facial nerve sensitivity)
- Troussea sign (tetany)
- seizure
- prolonged QT –> v tachycardia
hypothalmus –> pituitary –> adrenal glands
CRH –> ACTH –> cortisol –> free fatty acids & glucose released
Cushing’s disease
- pituitary overproduction ACTH (70%)
- ectopic production of ACTH –> carcinoid vs autonomous adrenal gland
hypercortisolism px
=anti-insulin stress hormone
- hyperglycemia
- hyperlipidemia
- hypoK, metabolic alkalosis
- leukocytosis from demargination
- fat redistribution (moon face, buffalo hump, truncal obesity, skin extremities)
- skin striae, dec wound healing, think skin
- osteoporosis
- HTN
- menstrual disorders
- erectile dysfunction
- polyuria (hyperglycemia –> osmotic diuresis)
-mixed mineral corticoid and androgen effects of cortisol
hypercortisolism diagnostic tests
- 24 hour urine cortisol
- low dose dexamethasone suppression test
- late night salivary cortisol
- ACTH levels
- high:pituitary OR ectopic source (high dose dexamethasone suppression test to differentiate)
-low:adrenal source (CT adrenals)
Cushing’s tx
surgically remove from source
pheochromocytoma dx
metanephrines in blood and urine
hyperaldosteronism dx
renin and aldosterone levels
Addison’s disease
=hypoadrenalism
-autoimmune, waterhouse-friedreich syndrome, TB, adrenoleukodystrophy, cancer
- weak, fatigue, altered mental status, hyper pigmentation (from inc ACTH), hypotension, hypoglycemia, hyperK, metabolic acidosis
- eosinophilia (you don’t have steroids, so you’re “allergic” to your adrenals)
-tx: hydrocortisone, fludrocortisone
cosyntropin stimulation test
cortisol is supposed to rise
- low cortisol, high ACTH, low aldosterone = primary adrenal insufficiency
- low cortisol, low ACTH, inc aldosterone = adrenal insufficiency secondary to pituitary insufficiency
pheochromotcytoma
episodic HTN headache sweating palpitations tremor
plasma catecholamines
24 hour urine metanephrines and catecholamines
biochemical testing –> then imaging with MRI or CT
MIBG scan to find extra-adrenal pheochromocytoma
tx: phenoxybenzamine (IV alpha blocker), propranolol (beta blocker), CCB, laproscopic removal
DB
polyuria, polyphagia, polydipsia
immunocompromised
2 fasting gluc > 125
1 gluc > 200
oral glucose testing – fast
Hg A1C > 6.5%
DB type 1
- insulin DEFICIENCY
- autoimmune
- childhood
- DKA
DB type 2
- insulin RESISTANCE
- acquired
- adult/ some kids
- obesity related
DB tx
- diet/exercise
- metformin (blocks gluconeogenesis),
- sulfonylureas (inc insulin release, weight gain)
- dipeptidyl peptidase inhibitors (sita/saxagliptans –inc insulin, dec glucagon via incretins)
- glitazones (risk in CHF)
- nateglinide/ repaglinide (weight gain, inc insulin release)
- acarbose, miglitol = alpha glucosidase inhibitors (diarrhea, flatus, abdominal pain) 3x/day
- amylin analog (pramlintide)
- insulin
- incretins usually have short half life
DKA
- inc fatty acid breakdown
- px: hyperventilation, altered mental status, metabolic acidosis, increased anion gap, hyperK (in blood not body), ketones
- tx: large volume saline, insulin, replace K, correct underlying cause (infections, noncompliance with meds)
- serum bicarb indicates severity
DB health maintenance
- pneumococcal vaccine
- yearly eye exam
- statins to get LDL < 100
- ACEI or ARB for BP < 130/80
- ACEI or ARB for microalbuminuria
- foot exam for neuropathy or ulcers
gastroparesis secondary to DB
- immobility of bowels
- bloating, constipation
- early satiety, vomiting
- abdominal discomfort
-tx: metoclopramide (inc gastric mobility) OR erythromycin (SE GI hypermotility; tiny dose)
